This is a little 4 - bit ALU i whipped up in about an hour and a half. Being 4 - bit it can only add up too 16, i plan on creating a new version that will hopefully be nicer looking and 8 - bit, which will be able to add up to 256. I may post a video on me using it, or a tutorial on how to build your own, as none of the tutorials i seen were any good.